An attitude controller eliminates a skid motion of a banked vehicle when travelling through a curve. The attitude controller includes a lateral acceleration sensor 34 configured to obtain lateral acceleration, as rightward or leftward accelerations, acting on a vehicle of a motorcycle 1; a bank angle detector 46 configured to detect a bank angle of the vehicle, and a longitudinal force controller 32 configured to decrease, independently of each of the wheels 8, 23, an absolute value of a longitudinal force as the sum of forward and backward forces acting on front and rear wheels 8 and 23 based on the obtained lateral acceleration and the detected bank angle. The lateral acceleration sensor 34 obtains the lateral acceleration. The bank angle detector 46 detects the bank angle of the vehicle. The longitudinal force controller 32 decreases, independently of each of the wheels, the absolute value of the longitudinal force as the sum of the forward and backward forces acting on each of the wheels in accordance with the lateral acceleration and the bank angle. This achieves attitude control.